1. Field of the Invention
The present invention relates to a tape carrier package (TCP) mounted on a flat-panel display apparatus, for example, a liquid crystal display apparatus. Particularly, the present invention relates to a tape carrier package of a slim type (slender type) capable of narrowing the non-image-displaying peripheral region in a liquid crystal display apparatus used in a notebook personal computer (PC), a car navigation system, such as a global positioning system (GPS), a small-sized television (TV) set and so on.
2. Description of the Related Art
In recent years, a flat-panel display apparatus substituting for a cathode ray tube (CRT) display has been intensively developed. Particularly, a liquid crystal display apparatus can achieve thin dimensions, light weight and low power consumption. Therefore, the market has rapidly been expanded starting the from use of the notebook PC's. With respect to a liquid crystal display apparatus, narrowing of the peripheral region has been expedited to further promote the advantage of saving space. For this purpose, the shape or mounting of the tape carrier package (TCP) or a driver printed circuit board (PCB), which are arranged at peripheral edges of a display panel, has been devised. As one example, in recent years, "a slim tape carrier package (TCP)" having a slim driver integrated circuit (IC) has been fabricated and used.
An explanation will be given of a conventional slim tape carrier package (TCP) in reference to FIGS. 3 and 4.
FIG. 3 is a schematic cross-sectional and perspective view viewing a slim tape carrier package (TCP) 100 from a face arranged with metal wiring. Further, FIG. 4 is a cross-sectional and perspective view similar to FIG. 3 showing a state of the tape carrier package (TCP) 100 before sealing is carried out by a potting resin 102.
The tape carrier package (TCP) 100 is fabricated substantially by the following steps (1) through (4).
(1) Fabrication of a Board Attached with Terminals and Wirings
An insulated film board 103, having a slender and substantially rectangular shape, is installed so as to have slits 131 for the terminals (i.e., for a group of input terminals and a group of output terminals). The slits 131 are located at end portions of the terminals and along the two long sides of the terminals. The insulated film board 103 is also installed with a slit 132 for an integrated circuit (IC) for mounting a driver integrated circuit (IC) 104 substantially at a central portion thereof.
The slits 131 for the terminals are arranged so that the group of the outside input terminals and the group of the outside output terminals both are comprised of metal foils, while a group of wirings 105 for the driver integrated circuit (IC), which group of wirings 105 reach from the groups 151 of input and output terminals to the slit 132, are formed on the insulated film board 103. Further, lead portions 152 extend from the group of wirings 105 into the slit 132 for the integrated circuit (IC).
(2) Formation of an Insulating Film (solder resist)
An insulating film 106 is formed to cover an entire region where the group of wirings 105 are formed on the insulated film board 103 (refer to FIG. 4). The insulating film 106 also covers portions 165 along short sides of the insulated film board 103 which are normally regions where the group of wirings 105 are not formed. By the portions 165, the insulating film 106 surrounds the slit 132 for the integrated circuit (IC) (refer to FIG. 4).
(3) Mounting of the Driver Integrated Circuit (IC)
The driver integrated circuit (IC) 104 is fitted into the slit 132 for the integrated circuit (IC). Then, bumps 141 of the driver integrated circuit (IC) and the lead portions 152 from the group of wirings 105 are connected by an Au/Sn eutectic bonding or similar (state of FIG. 4).
(4) Sealing by the Potting Resin
The potting resin 102 is poured into, and heated and cured, at a region of the bumps 141 of the driver integrated circuit (IC) and their surroundings (state of FIG. 3).
The tape carrier package (TCP) fabricated as described above is mounted and connected to pads located at an edge portion of a display panel.
The following problem is posed in the above-described conventional technology.
A considerably large deviation occurs in the width of wetting and spreading the potting resin for sealing the driver integrated circuit (IC). Accordingly, a dimension for the width D from the driver integrated circuit (IC) to the slit for the terminal needs to be set to include a margin for absorbing the deviation. Therefore, a total width of the slim tape carrier package (TCP) is increased by an amount of the margin.
When an amount of the potting resin 102 is reduced in order to reduce the wetting and spreading width, the reliability of sealing the driver integrated circuit (IC) 104 is deteriorated. Meanwhile, when the margin for absorbing the deviation is reduced, the potting resin 102 may partially cover the terminal metal foil and the reliability of terminal connection is deteriorated.
Although the slim driver integrated circuit (IC) is created by an enormous effort of technical development, the width of the tape carrier package (TCP) cannot be reduced to a degree of narrowing the driver integrated circuit (IC) because of the problem of sealing the driver integrated circuit (IC).